A Thermostat Sensor is a contact-type temperature sensor made up of two dissimilar metals such as aluminum, copper, nickel, or tungsten. When both metals are exposed to heat, the difference in their coefficients of linear expansion generates a mechanical bending movement.
Thermistors, also known as thermally sensitive resistors, are devices that change their physical appearance when exposed to temperature changes. The thermistors are made of ceramic materials such as nickel, manganese, or cobalt oxides that are coated with glass and can easily distort.
The majority of thermistor sensors have a negative temperature coefficient (NTC), which implies that as the temperature rises, their resistance lowers. However, a few thermistors have a positive temperature coefficient (PTC), which means their resistance increases as the temperature rise